Document kDJVOkpZR2pMnOMbkoEgxRoEE

COPY Dr. D.V.N. Hardy*''' Dr. H.R. Newman. Monsanto Ch8mlcal Company St. Louis, Missouri September 20, 1955 Dr. J.W. Barrett London Your memo September 8 to Mr. Nason AROCLOR TOXICITY Howard Nason has given me your memo of September 8. I will be happy to discuss this with Dr. Newman during his visit here. I think, however, there are several points that I can answer you now. You comment upon the difference in toxicity between Aroclor 1254 and 1242. This is not particularly surprising because in the earlier work it was found that toxicity increased with chlorination. Of course, from the standpoint of vol atility in the case of inhalation or absorption from the gut from the point of view of ingestion are important. Frankly, there was not too great a difference between the two compounds, however. As you know, the maximum allowable concentrate is 0.1 ml/cubic meter in the case of 1254, and as high as 10.0 mgm in the case of 1268. I think the former is too low and the latter is too high. In this country they don't use the MACs very routinely, but certainly in England I think it would be alright to consider 0.2 mgm/cubic meter as perfectly safe. I don't know how you would get any particular advantage in doing more work. What is it that you want to prove? I believe your work should be directed towards finding out what the concentrations are of Aroclor during different operations .whether it is industrial or painting,. The re ports you have seen from Kettering Laboratory are the re sult of approximately 015,000 to 020,000 expenditure by MCC. MCC's position can be summarized in this fashion. We know Aroclors are toxic but the actual limit has not been pre cisely defined. It does not make too much difference, it seems to me, because our main worry is what will happen if an individual developes any type of liver disease and gives a history of Aroclor exposure. I am sure the juries would not pay a great deal of attention to MACs. M0NS 095196 TOWOLDMONOQ46049 COPY Page 2 September 20, 1955 AROCLOR TOXICITY We, therefore, review every new Aroclor use from this point of view. If it is an industrial application where we can get air concentrations and have some reasonable expectation that the air concentrations will stay the same, we are much more liberal in the use of Aroclor. If, however, it is distributed to householders where it can be used in almost any shape and form and we are never able to know how much of the concentration they are exposed to, we are much more strict. No amount of toxicity testing will obviate this last dilemma and therefore I do not believe any more test ing would be Justified. Let's see what our discussions with Dr. Newman and yourself bring out. ,, KEKsk R. Emmet Kelly, M.D. MONS 095197 TOWOLDMON0046050